Tip: How to reduce engine noise.

iRide Customs

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A friend of mine was over last night and he mentioned something that I never really thought about.

Has anyone ever seen the rubber bushings that were sometimes iserted inbetween the fins of two stroke motorcycle engines? Well I have seen them a million times but never really knew why they were there. Well, my friend Luke enlightened me...they are for sound deadening. I tried it on my Dax 70cc and it reduced that high pitched engine whine by about 50% and I only put it in about 5 different places.

To get an idea of how it works, simply grab the 2 outside fins on the head of a Dax 70cc (before the engine warms up, obviously) and hear the difference.

I am going to put bushing between every fin on my engine. Yes I am going to use bushings that won't melt.

Dan
 
Yes it does work. Bond them in with a dot of high temp silicone so they do not vibrate out.
 
But what of cooling? I would think anything between them cooling fins would obstruct cooling.
We need pics and where to go ect.
 
It only takes small pieces of rubber to acheive the desired result. I don't think it impairs cooling at all. Richard and I just got back from a 15 mile ride and had no problems with overheating.

I will post a couple of pics here in a little while.

Dan
 
Ok...here is a pic or 3 of what I did. I tried to make the rubber small so it would not interfere with air flow too much.
 

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That's it? AWESOME!! I pictured these rubber inserts going all the way around the fins.
This is a real dumb question,but my brain isn't working tonight. Where did you get those rubber pieces? The answer I bet is so obvious but right now I'm drawing a blank for some reason.
 
That's it? AWESOME!! I pictured these rubber inserts going all the way around the fins.
This is a real dumb question,but my brain isn't working tonight. Where did you get those rubber pieces? The answer I bet is so obvious but right now I'm drawing a blank for some reason.

Not so obvious...the rubber pieces were scavenged from where I work. It's gasket material for the man holes on 1,000,000 gal. tanks.
 
Temperature gauge

How about a little experiment: Installing a temperature gauge (has anybody done this?) and do a before and after dampening. I think you would have to install the sensor in the back part of the engine as this would be the part affected by the possible lack of airflow. My guess, you would see a difference at normal operating speeds. I would volunteer but I'm still piecing my bike together, and it's going very sloooowly.....
 
When noise became an issue in the mid '80s many air cooled M/Cs used rubber damping blocks in the fins. There was never an over heating problem. It does not take alot of rubber to be effective.
 
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